meormuslih

I just need some confirmations from you guys. Let's say some one take Na+ of 1 mol per day for a week. Will the tonicity of the urine compared to the plasma matter? Or is it still possible that while maintaining the osmotic balance of the body, the urine can be either hypotonic, isotonic or hypertonic? I think that the tonicity of the urine will highly dependant on the water needs of the body, not the concentration of stuffs needed to be excreted. However, I'm unsure since Na+ is also osmotically active, the ions might hold water from being reabsorbed, making the urine more isotonic or hypotonic. This I believe, means that hypertonic (in comparison to plasma) urine is highly unlikely . I really hope that you guys understand my problems, hehe...